If your previous case was a chapter 7 and you received a discharge, you must wait eight years from the date the previous case was filed to file another chapter 7. You must wait four years from a chapter 7 to a chapter 13 bankruptcy.
If your previous case was a chapter 13 and you received a discharge, you must wait six years from the date the chapter 13 was filed to file a chapter 7. You must wait two years from one chapter 13 to another.
If you did not receive a discharge in your previous case, there is no time restriction on filing a new bankruptcy. There are also waiting periods after chapter 11 and chapter 12 cases, depending on what the chapter the new case will be, but those cases are less common, and as with most bankruptcy laws, there are exceptions to the time limits above. Talk to an experienced bankruptcy lawyer if you have a questions about how long you need to wait between filing cases.